Apparatus for delivering a volatile material

ABSTRACT

An apparatus for delivering a volatile material in a continuous manner is disclosed. The apparatus includes a delivery engine having a reservoir for containing a volatile material; a rupturable substrate secured to the reservoir; a rupture element positioned adjacent to the rupturable substrate; and a breathable membrane enclosing the reservoir, rupturable substrate and rupture element.

FIELD OF THE INVENTION

The present invention relates to an apparatus having a breathablemembrane for delivering a volatile material to the atmosphere in acontinuous manner.

BACKGROUND OF THE INVENTION

It is generally known to use a device to evaporate a volatile materialinto a space, particularly a domestic space, in order to deliver avariety of benefits, such as air freshening for perfuming of the air.Non-energized systems, for example, systems that are not powered byelectrical energy, are a popular way for the delivery of volatilematerials into the atmosphere. These systems can be classified intothose that require human actuation, such as aerosols, and those which donot required human actuation, such as wick based systems and gels. Thefirst type delivers the volatile materials on demand and the second typein a more continuous manner.

One type of apparatus for delivering a volatile material is disclosed inU.S. Pat. No. 4,161,283. It discloses an article for delivering avolatile material comprising a reservoir, polymeric sheet or membrane,and a barrier layer releasably bonded to the outer wall of thereservoir. One drawback with this type of article is its susceptibilityto de-lamination and leakage because the volatile materials are incontact with the membrane during storage or non-use. Another drawbackmay be that volatile materials build up in the membrane during storage,resulting in a spike in intensity immediately after the barrier layer isremoved. Another drawback may be that the peel force makes it isdifficult to remove the barrier layer without damaging the polymericsheet or membrane. Yet another drawback may be the selectivity of themembrane in that it does not easily allow low vapor pressure volatilematerials to diffuse through the polymer.

Another apparatus for delivering a volatile material is disclosed inU.S. Pat. No. 4,824,707. It discloses a decorative air freshener unithaving a capsule containing a supply of volatile fragrance. The capsuleis trapped between a microporous sheet and a backing sheet. The capsuleis ruptured by applied force and the released fragrance is absorbed intothe microporous sheet which gradually exudes the fragrance. Thisapproach may limit the longevity of a scent since liquid is released allat once to the microporous sheet, and there is little control over themanner in which the liquid will wet the microporous sheet.

As such, there exists a need for an apparatus for delivering, over aperiod of time, a consistent release of volatile materials having abroad range of molecular weights and vapor pressures.

SUMMARY OF THE INVENTION

According to one embodiment of the invention, there is provided anapparatus for delivering a volatile material comprising a deliveryengine having a reservoir for containing a volatile material; arupturable substrate secured to the reservoir; a rupture elementpositioned adjacent to the rupturable substrate; and a microporousmembrane enclosing the reservoir, rupturable substrate, and ruptureelement. The apparatus may deliver a volatile material in a continuousmanner. In one aspect of the invention, the apparatus comprises ahousing for the delivery engine. The housing may have vents forfacilitating the diffusion of volatile materials from the deliveryengine.

According to another embodiment of the invention, there is provided anapparatus for delivering a volatile material comprising a deliveryengine having a liquid reservoir for containing a volatile material; arupturable substrate secured to the reservoir; a compressible flangepositioned adjacent to the rupturable substrate for rupturing therupturable substrate; a collection basin in fluid communication with theliquid reservoir upon rupturing the rupturable substrate; and abreathable membrane enclosing the liquid reservoir, rupturablesubstrate, rupture element, and collection basin.

According to yet another embodiment of the invention, there is providedan apparatus for delivering a volatile material comprising a deliveryengine having a liquid reservoir for containing a volatile materialcomprising a single opening; a rupturable substrate enclosing the singleopening; a rupture element; a collection basin in fluid communicationwith the liquid reservoir upon rupturing the rupturable substrate; and abreathable membrane enclosing the liquid reservoir, rupturablesubstrate, rupture element, and collection basin. The breathablemembrane has an evaporative surface area of about 15 cm² to about 35 cm²and has an average pore size of about 0.02 microns. The apparatus alsocomprises a housing for receiving and releasably engaging the deliverysystem. The housing has a rib for guiding the delivery engine and anotch for compressing the rupture element upon insertion of the deliveryengine into the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with the claims particularly pointingout and distinctly claiming the invention, it is believed that thepresent invention will be better understood from the followingdescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 shows a perspective view of one embodiment of an apparatus inaccordance with the present invention.

FIG. 2 shows an exploded, perspective view of one embodiment of adelivery engine in accordance with the present invention.

FIG. 3 shows a cross-sectional view of another embodiment of a ruptureelement in accordance with the present invention.

FIG. 4 shows a cross-sectional view of another embodiment of a ruptureelement in accordance with the present invention.

FIG. 5 shows a side elevational view of the delivery engine in FIG. 2 inaccordance with the present invention.

FIG. 6 shows a front elevational view of one embodiment of a housing inaccordance with the present invention.

FIG. 7 shows a top plan view of the housing in FIG. 6 .

FIG. 8 shows a cross-sectional view along lines 8-8 of the apparatus inFIG. 1 .

FIG. 9 shows the cross-sectional view in FIG. 8 where the deliveryengine is being received by the housing.

FIG. 10 is a graph showing evaporation profiles of volatile materialshaving varying vapor pressure ranges evaporated from a breathablemembrane in accordance with the present invention

FIG. 11 is a graph showing evaporation profiles of volatile materialsevaporated from a polyethylene membrane and from a breathable membranein accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a non-energized apparatus for thedelivery of a volatile material to the atmosphere in a continuous,non-energized manner. “Non-energized” means that the apparatus ispassive does not require to be powered by a source of external energy.In particular, the apparatus does not need to be powered by a source ofheat, gas, or electrical current, and the volatile material is notdelivered by aerosol means. Further, as used in this specification andthe appended claims, the singular forms “a”, “an”, and “the” includeplural references unless the content clearly dictates otherwise. Thus,for example, “a volatile material” may include more than one volatilematerial

The apparatus of the present invention delivers a volatile material in asubstantially continuous manner when the apparatus is in a restingposition (i.e. the apparatus is not being moved). The emission level ofvolatile materials may exhibit a uniform intensity until substantiallyall the volatile materials are exhausted. The continuous emission of thevolatile materials can be of any suitable length, including but notlimited to, up to: 20 days, 30 days, 60 days, 90 days, shorter or longerperiods, or any period between 30 to 90 days.

The apparatus of the present invention is suitable for purposes ofproviding fragrances, air fresheners, deodorizers, odor eliminators,malodor counteractants, insecticides, insect repellants, medicinalsubstances, disinfectants, sanitizers, mood enhancers, and aromatherapyaids, or for any other purpose using a volatile material that acts tocondition, modify, or otherwise change the atmosphere or theenvironment. For purposes of illustrating the present invention indetail, but without intending to limit the scope of the invention, theinvention will be described in an air freshening system for deliveringliquid containing perfume raw materials.

Referring to FIG. 1 , an apparatus 10 in accordance with the presentinvention is shown. The apparatus 10 includes a delivery engine 100 anda housing 200.

Delivery Engine

Referring to FIG. 2 , the delivery engine 100 comprises a width, lengthand depth along an x-axis, y-axis, and z-axis, respectively. The width,length, and depth may be such that the delivery engine 100 is consideredcompact and/or portable. By “compact” or “portable”, it is meant thatthe delivery engine 100 can be conveniently and comfortably carried in apocket, purse, or the like. The delivery engine 100 can be constructedas a disposable, single-use item or one that it is replenished with avolatile material.

The delivery engine 100 may include a lip 102 that defines the outerperimeter of the delivery engine 100 and may circumference a reservoir110 for containing a volatile material as well as a collection basin112. The delivery engine 100 may also include a rupturable substrate 120secured to the reservoir 110; a rupture element 130 positioned adjacentto the rupturable substrate 120; and a breathable membrane 140 securedto the lip 102 and enclosing the rupturable substrate 120, reservoir110, and collection basin 112.

The body 104 of the delivery engine 100 can be thermoformed, injectionmolded, or blow molded with any known material. In some embodiments, thebody 104 includes all structural aspects of the delivery engine 100minus the rupturable substrate 120, the rupture element 130, andbreathable membrane 140. In other embodiments, the body 104 includes therupture element 130. The body 104 may be made of a multi layer materialwhich may include a barrier layer to prevent evaporation of a volatilecomponent and at least one outer layer that allows a rupturablesubstrate 120 to be heat-sealed to the body 104. A suitable sealantlayer would include a layer of polyethylene or polypropylene or anysuitable polyolefin sealant that allows for a leak proof seal of thereservoir 110. Suitable materials to form the body 104 of the deliveryengine 100 include plastics, such as Pentaplast Pentaform® 2101available from Klockner. In some embodiments, the material is colored ornon-colored see-through plastic. The see-through material permitsobservation of the liquid and end-of life.

Reservoir

The delivery engine 100 may comprise a reservoir 110 for holding avolatile material. The reservoir 110 includes a width, length, and depthalong the x-axis, y-axis, and z-axis, respectively. The reservoir 110may be elongate in that its width to length ratio is about 2:1 to about4:1, alternatively about 1.5:1 to about 2.5:1. The reservoir 110 mayhave a width of about 45 mm to about 55 mm, alternatively about 51 mm; alength of about 15 mm to about 30 mm to about, alternatively about 23mm; a depth of about 5 mm to about 15 mm, alternatively about 11 mm. Thedimensions of the reservoir 110 may be such that it holds about 2 ml toabout 50 ml of liquid containing a volatile material. Alternatively, thereservoir 110 may hold about 2 ml to about 30 ml, alternatively about 2ml to about 10 ml, alternatively about 2 ml to about 8 ml, alternativelyabout 4 ml to about 6 ml, alternatively about 2 ml, alternatively about6 ml of liquid containing a volatile material.

The reservoir 110 may include a bottom 114 and a single opening 116. Thereservoir 110 may also have a ridge 122 circumferencing the singleopening 116 or the upper edge of the reservoir 110. This ridge 122 mayprovide a generally flat surface upon which a rupturable substrate 120may be secured. The ridge 122 allows the secured area of the rupturablesubstrate 120 to be located away from the inner walls of the reservoir110 where the volatile material would be held.

It is contemplated that the delivery engine 100 of the present inventionmay comprise two or more reservoirs (not shown) which can be filled withthe same or different volatile materials. The reservoirs may have anyconfiguration that contacts the breathable membrane 140 upon rupture.For example, the reservoirs may be opposedly connected for use in aflippable device. In such a device, the breathable membrane 140 isfluidly connected between the reservoirs.

Rupturable Substrate

Still referring to FIG. 2 , the delivery engine 100 includes arupturable substrate 120. The rupturable substrate 120 may be configuredin any manner that prevents the volatile material in the reservoir 110from contacting the breathable membrane 140 prior to activating orrupturing the delivery engine 100. In one embodiment, the rupturablesubstrate 120 may enclose the reservoir, prior to activation, byextending across the single opening 116 securing to the ridge 122 of thereservoir 110. The rupturable substrate 120 may be secured by a layer ofadhesives, heat and/or pressure sealing, ultrasonic bonding, crimping,and the like or a combination thereof.

The rupturable substrate 120 can be made of any material that ruptureswith applied force, with or without the presence of an element to aid insuch rupture. Because the rupturable substrate 120 is intended tocontain a volatile material while in storage, it may be made from alayer of barrier material that prevents evaporation of the volatilematerial prior to its intended use and a layer of heat-sealable layer.Such materials may be impermeable to vapors and liquids. Suitablebarrier materials for the rupturable substrate 120 include a flexiblefilm, such as a polymeric film, a flexible foil, or a composite materialsuch as foil/polymeric film laminate. Suitable flexible foils include ametal foil such as a foil comprised of a nitrocellulose protectivelacquer, a 20 micron aluminum foil, a polyurethane primer, and 15 g/m2polyethylene coating (Lidfoil 118-0092), available from Alcan Packaging.Suitable polymeric films include polyethylene terephtalate (PET) films,acrylonitrile copolymer barrier films such as those sold under thetradename Barex® by INOES, ethylene vinyl alcohol, and combinationsthereof. It is also contemplated that coated barrier films may beutilized as a rupturable substrate 120. Such coated barrier filmsinclude metalized PET, metalized polypropylene, silica or alumina coatedfilm may be used. Any barrier material, whether coated or uncoated, maybe used alone and or in combination with other barrier materials.

Rupture Element

The rupturable substrate 120 may be breached to release a volatilematerial by actuating a rupture element 130. The rupture element 130 canbe injection, compression, or pressure molded using a polyolefin, suchas polyethylene or polypropylene; polyester; or other plastics as knownto be suitable for molding. The rupture element 130 could also be madeby thermoforming with a discrete cutting step to remove parts notwanted.

The rupture element 130 may be positioned in a space 132 formed in thedelivery engine body 104 that is adjacent to the rupturable substrate120 and subjacent a breathable membrane 140. The space 132 may beconfigured such that the rupture element 132 is nested within the space132 and enclosed by a breathable membrane 140, thus requiring no othermeans to hold the rupture element 132 in the delivery engine 100. In oneembodiment, the rupture element 130 is positioned between and in contactwith said rupturable substrate 120 and said breathable membrane 140. Arupture element 130 that is directly adjacent to the breathable membrane140 may facilitate wetting of the breathable membrane 140. Morespecifically, liquid may wick between rupture element 130 and thebreathable membrane 140 allowing for maintenance of a larger wettedsurface area of the breathable membrane 140.

The rupture element 130 may be configured in any manner such that a usercan manually actuate the rupture element 130 and breach the rupturablesubstrate 120 with relative ease. In one embodiment, a user may actuatethe rupture element 130 by manually compressing it. In otherembodiments, the rupture element 130 may breach the rupturable substrate120 through contact with an element provided in a delivery enginehousing that engages and compresses the rupture element 130. Suitablecompression forces to breach the rupturable substrate 120 with a ruptureelement 130 may be less than about 25N, alternatively, less than about20N, alternatively less than about 15N, alternatively less than about10N, alternatively less than about 5N, alternatively from about 1N toabout 15N, alternatively, from about 1N, to about 10N, alternatively,from about 1N to about 5N.

The compression force can be measured using an electromechanical testingsystem, QTest Elite 10, available from MTS, along with a modified UL 283finger probe made of polyamide. The UL 283 finger probe is described inStandard for Air Fresheners and Deodorizers, UL Standard 283, FIG. 10.1(UL Mar. 31, 2004). As described in UL 283, FIG. 10.1, the radius of thefinger tip is 3.5 mm; height of the finger tip is 5 mm; depth of thefinger tip is 5.8 mm. However, unlike the finger probe described in theaforementioned text, the modified UL 283 finger probe does not includeany articulating joints. Instead, it is in a fixed position that isperpendicular to the rupture element 130 when testing is conducted. Thetesting occurs at ambient temperatures (23±2° C.). The perimeter of adelivery engine 100 is rested on a support fixture, without directlycontacting or directly securing the rupture element 130 to the supportfixture. The crosshead speed of the electromechanical testing system isset at 30 mm/min. The modified UL 283 finger probe is moved towards therupture element 130 to contact a region where displacement is desiredfor rupturing a rupturable substrate 120. Where a flange 134 such as theone described herein is utilized, the desired region of displacement isthe mid-point of the flange 134. The mid-point is the point that is halfway between the proximal end and distal end 136. For example, where aflange 134 is 2 cm from proximal end to distal end 136, the mid-point islocated at 1 cm. The machine is run until the rupture element 130 isdisplaced by 6 mm. Zero displacement is defined as the point at which0.1N of force (i.e. preload) is applied. The load at the first peakwhere the rupturable substrate 120 is broken is recorded as the force torupture. Those of ordinary skill in the art will appreciate thatcompression forces will vary depending on the physical properties andplacement of the breathable membrane 140, rupture element 130, andrupturable substrate 120 in a delivery engine 100.

There are numerous embodiments of the rupture element 130 describedherein, all of which are intended to be non-limiting examples. FIG. 2shows one non-limiting embodiment of the rupture element 130. In thisembodiment, the rupture element 130 includes a flange 134 hinged to therupture element 130. The flange 134 may be injection molded and mayinclude a distal end 136. The distal end 136 may include one or morepiercing elements 138 located in the z-direction or towards therupturable substrate 120. In one embodiment, the distal end 136 mayinclude two spaced apart piercing elements 138 in the z-direction. In analternate embodiment, the distal end 136 may form a single point (notshown) along the x-y plane. A user may manually compress or pressdownward in the z-direction on the flange 134 such that the rupturablesubstrate 120 is breached and a volatile material is released to thebreathable membrane 140.

It is contemplated that the rupture element 130 may include more thanone flange 134 where additional points of rupture are desired. Forexample, the rupture element 130 may include a first compressible flangeand a second compressible flange opposedly hinged to said ruptureelement (not shown).

FIG. 3 shows another embodiment of a rupture element 330 which includesone or more piercing elements 332 supported on a correspondingspring-like part 334. The spring-like part 334 may be a metal coil,polyolefin or polyurethane foam, injection molded bristles, injectionmolded plastic spring or hinge parts, or the like. Upon pressing therupture element 330 towards the rupturable substrate 320, one or morepiercing elements 332 will puncture the rupturable substrate 320 andthen return to its original position.

FIG. 4 shows another embodiment of a rupture element 430 where it isintegrally formed with the reservoir 410. This can be accomplished bythermoforming, pressure forming, injection molding or any known means offorming plastic parts. The rupture element 430 in this embodiment, is asharp piercing structure extending opposite from the interior bottom 414of the reservoir. A user may compress the bottom 414 of the reservoir410 to pierce the rupturable substrate 420 with the rupture element 430.This embodiment eliminates having to manufacture a separate ruptureelement 430, yet it performs the same function.

Collection Basin

Now referring to FIG. 5 , the delivery engine 100 may optionally includea collection basin 112 to collect volatile materials from the reservoir110 after the rupturable substrate 120 is compromised. The collectionbasin 112 may be any size, shape or configuration, and may be made ofany suitable material, so long as it is in fluid communication with thereservoir 110 and the breathable membrane 140 upon rupturing therupturable substrate 120. It may be sized to collect any suitable volumeof a volatile material to provide a controlled volume of the volatilematerial to the breathable membrane 140. In one embodiment, thecollection basin 112 may be sized to collect about 1 ml to about 4 ml ofvolatile materials, alternatively about 1 ml to about 3 ml,alternatively about 1 ml to about 2.5 ml, alternatively about 1.5 ml toabout 1.8 ml.

In one embodiment, the collection basin 112 may include a bottom 118 inthe z-direction and a top that opens towards a breathable membrane 140.The breathable membrane 140 may lie across the open top, enclosing thecollection basin 112 so liquid cannot flow freely out through thebreathable membrane 140. The collection basin 112 may be integrallyconstructed with the body 104 of the delivery engine 100 in a thermoformpart.

As shown in FIG. 5 , in one embodiment, the collection basin 112 ispositioned downwardly or opposite the y-direction from the reservoir110. When the delivery engine 100 is placed upright, a volatile materialnaturally flows down the reservoir 110 into the collection basin 112ensuring a controlled, continual dosing of the breathable membrane 140.Further, the collection basin 112 has depth along the z-axis which issmaller in depth than the reservoir 110. The bottom 118 of thecollection basin lies closer to the breathable membrane 140 than thereservoir bottom 114, thus forming a step in the delivery engine 100.The proximity of the collection basin bottom 118 with the breathablemembrane 140 helps to ensure a continual supply of volatile material andwet more surface area of the breathable membrane 140, even when verylittle volatile material remains in the delivery engine 100. When theliquid contact area of the breathable membrane 140 is greater, theevaporation rate of volatile materials is higher and fragrance intensitycan be maintained over longer periods.

Membrane

The delivery engine 100 may include a breathable membrane 140. Thebreathable membrane 140 is vapor permeable and prevents free flow ofliquid out of the membrane 140, thus addressing leakage problems.

The breathable membrane 140 may be secured to the lip 102 of thedelivery engine 100 in the same manner as the rupturable substrate 120is secured to the ridge 122 of the reservoir 110. The breathablemembrane 140 encloses the reservoir 110, rupturable substrate 120,rupture element 130, and collection basin 112. In this way, therupturable substrate 120 may be breached by compressing the breathablemembrane 140 and the rupture element 130. Once breached, the volatilematerial flows out of the reservoir 110, contacts the breathablemembrane 140, and is delivered to the atmosphere. Because the breathablemembrane 140 is shielded from the volatile material until the rupturablesubstrate 120 is breached, the fragrance intensity may build slowly fromzero to its equilibrium rate of release when the breathable membrane 140is fully wetted.

While not wishing to be bound by theory, the physical characteristics ofa membrane may affect the diffusion rate of volatile materials throughthe membrane. Such characteristics may include materials used, poresize, thickness, and evaporative surface area.

The breathable membrane 140 may be filled with any suitable filler andplasticizer known in the art. Fillers may include finely divided silica,clays, zeolites, carbonates, charcoals, and mixtures thereof. In oneembodiment, the breathable membrane 140 may be filled with about 50% toabout 80%, by total weight, of silica, alternatively about 60% to about80%, alternatively about 70% to about 80%, alternatively about 70% toabout 75%.

In one embodiment, the breathable membrane 140 may include a microporousmembrane. The microporous membrane is vapor permeable and capable ofwicking liquid, yet prevents free flow of liquid out of the membrane.The microporous membrane may have limited selectivity leaving behindfewer perfume materials. Membranes that are selective, such astraditional polyethylenes, may inhibit high molecular weight volatilematerials and materials with low solubility in polyethylene fromdiffusing through. This may limit perfume formulations, for example inthe field of air fresheners where it is typically desired to useformulations having a wide variety of volatile materials havingdifferent volatilities. For example, some membranes may preclude thediffusion of alcohols, such as linalool and dihydromyrcenol which arewidely used in perfume applications. The microporous membrane may havean average pore size of about 0.01 to about 0.06 microns, alternativelyfrom about 0.01 to about 0.05 microns, alternatively about 0.01 to about0.04, alternatively about 0.01 to about 0.03, alternatively about 0.02to about 0.04 micron, alternatively about 0.02 microns.

The breathable membrane 140 may have a thickness in the z-direction, ofabout 0.01 mm to about 1 mm, alternatively between about 0.1 mm to 0.4mm, alternatively about 0.15 mm to about 0.35 mm, alternatively about0.25 mm.

Those of ordinary skill in the art will appreciate that the surface areaof the breathable membrane 140 can vary depending on the user preferredsize of the delivery engine 100. In some embodiments, the evaporativesurface area of the breathable membrane 140 may be about 2 cm² to about100 cm², alternatively about 10 cm² to about 50 cm², alternatively about10 cm² to about 45 cm², alternatively about 10 cm² to about 35 cm²,alternatively about 15 cm² to about 40 cm², alternatively about 15 cm²to about 35 cm², alternatively about 20 cm² to about 35 cm²,alternatively about 30 cm² to about 35 cm², alternatively about 35 cm².

Suitable breathable membranes 140 for the present invention include amicroporous, ultra-high molecular weight polyethylene (UHMWPE)optionally filled with silica as described in U.S. Pat. No. 7,498,369.Such UHMWPE membranes include Daramic™ V5, available from Daramic,Solupor®, available from DSM (Netherlands), and Teslin™, available fromPPG Industries, and combinations thereof. It is believed that thesemembranes allow a volatile material to freely dissipate, whilecontaining liquid within the delivery engine 100.

Other suitable breathable membranes 140 include any permeable polymeric,thermoplastic, or thermoset material, including acetal, acrylic,cellulosic, fluoroplastic, polyamide, polyester, polyvinyl, polyolefin,styrenic, etc, alone, co-extruded, woven or non-woven, mixed or incombination with elastomers, rubber, solids, silicas, or combinationsthereof. Also suitable are Hytrel™ available from Dupont or Lotryl™available from Arkema.

In one aspect of the invention, the breathable membrane 140 may includea dye that is sensitive to the amount of volatile material it is incontact with to indicate end-of-life. Alternatively, the breathablemembrane 140 may change to transparent when in contact with a fragranceor volatile material to indicate diffusion is occurring. Other means forindicating end-of-life that are known in the art are contemplated forthe present invention.

Housing

Now referring to FIGS. 6 to 9 , the apparatus 10 of the presentinvention may include a housing 200 for releasably engaging the deliveryengine 100. The housing 200 may comprise a width, length and depth alongan x-axis, y-axis, and z-axis, respectively (as shown in FIG. 1 ). Thehousing 200 can be made of any suitable material such as glass, ceramic,wood, plastic, composite material, etc, and can have any size, shape andconfiguration suitable for encasing the delivery engine 100. The housing200 can be rigid or flexible and can be made of material which allowsthe transfer of volatile materials to the surrounding environment. Thehousing 200 may include a base 210, a hollowed core 240 supported on thebase 210 and nested internally within a shell 220. The housing 200 mayalso include a notch 270 and vents 260.

Shell and Hollowed Core

As seen in FIGS. 8 and 9 , the housing 100 may include a hollowed core240 supported on a base 210 and nested internally within a shell 220.The shell 220 may have a front wall 222 and a rear wall 224, both ofwhich may be generally coextensive with a front wall 242 and a rear wall244 of the hollowed core 240. The hollowed core 240 and shell 220 may beelliptically cylindrical and include a receiving end 230 for receivingthe delivery engine 100. The receiving end 230 may be disposed remotelyfrom the base 210 of the housing 200.

Ribs and Notches

The inner face of the rear wall 244 of the hollowed core 240 may includeone or more retaining ribs 246 for guiding the delivery engine 100downward into its final in-use position as seen in FIG. 9 . In oneembodiment, the retaining ribs 246 may include a first retaining rib anda second retaining rib positioned on the inner face of the rear wall 244and which both extend longitudinally along the y-axis. The first andsecond retaining ribs may be positioned at the intersection of the front242 and rear walls 244 of the hollowed core 240 to receive the lip 102of the delivery engine 100.

The housing 200 may also include a notch 270, or a plurality of notches,to engage or compress the rupture element 130 as the delivery engine 100is being received in the housing 200. In this way, a user is notrequired to manually activate the delivery engine 100 prior to itsinsertion into the housing 200. The notch 270 may be configured in anymanner such that the delivery engine 100 can be inserted into thehousing 200 with relative ease while the notch 270 compresses therupture element 130 and breaches the rupturable substrate 120.

Suitable insertion forces to insert the delivery engine 100 whichcompresses the rupture element 130 and breaches the rupturable substrate120 include less than about 25N, alternatively less than about 20N,alternatively less than about 15N, alternatively less than about 5N,alternatively from about 1N to about 25N, alternatively from about 1N toabout 15N, alternatively from about 5N to about 20N, alternatively fromabout 5N to about 15N, alternatively about 8 to 15 N.

The insertion force can be measured using an electromechanical testingsystem, QTest Elite 10 available from MTS. The delivery engine 100 isclamped to the testing system and placed in the receiving end of thehousing without any force against any notch 270 or elements that breachor help breach the rupturable substrate 120. The crosshead speed of theelectromechanical testing system is set at 50 mm/min. The roomtemperature is 23±2° C. The machine is run until the rupturablesubstrate 120 is breached. Zero displacement is defined as the point atwhich 0.1N of force (i.e. preload) is applied. The load at the firstpeak where the rupture substrate 120 is broken is recorded as the forceto rupture. Those of ordinary skill in the art will appreciate thatinsertion forces will vary depending on the physical properties andplacement of the notch 270, breathable membrane 140, rupture element130, and rupturable substrate 120.

In one embodiment, the notch 270 may be laterally off-set from thecenter of the front wall 242 of the hollowed core 240, so that lessprojection of the notch 270 in the z-direction is required whenmanufacturing. Thus, the breathable membrane 140 does not need to bestretched as far, resulting in less likelihood of damage.

The notch 270 and ribs 246 are configured such that the delivery engine100 does not need to bend when inserting, resulting in lower insertionforce. As the delivery engine 100 is inserted into the housing 200, thenotch 270 compresses the breathable membrane 140 and the rupture element130 in the direction of the reservoir 110 to breach the rupturablesubstrate 120 and release volatile materials to the breathable membrane140. During insertion of the delivery engine 100, the ribs 246 guide thedelivery engine 100 into contact and against the notch 270, maintainingthe lateral position of the delivery engine 100 so the notch 270 fullyengages the rupture element 130.

Vents

The housing 200 may have a plurality of vents 260 or apertures whichalign in a first, open position to facilitate delivery of the volatilematerial from the breathable membrane 140 to the atmosphere of the roomor rooms that require treatment. Increasing the effective size of thevents 260, may increase the delivery of volatile material. Conversely,decreasing the effective size of the vents 260, may decrease thedelivery of volatile material.

The vents 260 may be disposed anywhere on the housing 200. In theembodiment shown in FIGS. 6 to 9 , the vents 260 are disposed on thefront walls 222, 242 of shell 220 and hollowed core 240. The numberand/or size of the vents 260 are not fixed. The size of the vents 260can be controlled by the user through a variety of means. A user mayopen, partially open, partially close, or close the one or more vents260 by sliding the shell 220 downwardly along the y-axis towards thebase 210 such that the desired amount of emission is delivered to thelocation needing treatment. The housing 200 may also be constructed toenable open and closing of the vents 260 by rotation of the shell 240around the x-axis (not shown). In addition to the vents 260, the housing200 may have other means for visual inspection of the delivery engine100.

The housing 200 may also include a clicking mechanism (not shown) tosignal to the user that the housing 200 is in the desired open or closedposition. Such clicking mechanism may include a first mating part (notshown) disposed along the outer face of the hollowed core 240 and asecond mating part (not shown) disposed along the inner face of theshell 220. The mating parts may frictionally engage the walls of theshell 220 and hollowed core 240 as they slide against one another. Whenthe desired open or closed position is reached the mating parts mayreleasably lock into place and may provide a clicking sound.

Volatile Material

The apparatus 10 and/or the delivery engine 100 of the present inventiondeliver a volatile material to the atmosphere in a continuous manner.The term “volatile material” as used herein, refers to a material thatis vaporizable at room temperature and atmospheric pressure without theneed of an energy source. The volatile material may be a compositioncomprised entirely of a single volatile material. The volatile materialmay also be a composition comprised entirely of a volatile materialmixture (i.e. the mixture has more than one volatile component).Further, it is not necessary for all of the component materials of thecomposition to be volatile. Any suitable volatile material in any amountor form, including a liquid or emulsion, may be used. Liquid suitablefor use herein may, thus, also have non-volatile components, such ascarrier materials (e.g., water, solvents, etc). It should also beunderstood that when the liquid is described herein as being“delivered”, “emitted”, or “released,” this refers to the volatilizationof the volatile component thereof, and does not require that thenon-volatile components thereof be emitted.

The volatile material can be in the form of perfume oil. Mostconventional fragrance materials are volatile essential oils. Thevolatile material can be a volatile organic compound commonly availablefrom perfumery suppliers. Furthermore, the volatile material can besynthetically or naturally formed materials. Examples include, but arenot limited to: oil of bergamot, bitter orange, lemon, mandarin,caraway, cedar leaf, clove leaf, cedar wood, geranium, lavender, orange,origanum, petitgrain, white cedar, patchouli, neroili, rose absolute,and the like. In the case of air freshener or fragrances, the differentvolatile materials can be similar, related, complementary, orcontrasting.

The volatile material may also originate in the form of a crystallinesolid, which has the ability to sublime into the vapor phase at ambienttemperatures or be used to fragrance a liquid. Any suitable crystallinesolid in any suitable amount or form may be used. For example, suitablecrystalline solids include but are not limited to: vanillin, ethylvanillin, coumarin, tonalid, calone, heliotropene, musk xylol, cedrol,musk ketone benzohenone, raspberry ketone, methyl naphthyl ketone beta,phenyl ethyl salicylate, veltol, maltol, maple lactone, proeugenolacetate, evemyl, and the like.

It may not be desirable, however, for volatile materials to be closelysimilar if different volatile materials are being used in an attempt toavoid the problem of emission habituation. Otherwise, the peopleexperiencing the emissions may not notice that a different material isbeing emitted. The different emissions can be provided using a pluralityof delivery systems each providing a different volatile material (suchas, musk, floral, fruit emissions, etc). The different emissions can berelated to each other by a common theme, or in some other manner. Anexample of emissions that are different, but complementary might be acinnamon emission and an apple emission.

In addition to the volatile material of the present invention, thedelivery engine 100 may include any known malodor composition toneutralize odors. Suitable malodor compositions include cyclodextrin,reactive aldehydes and ionones.

While not wishing to be bound by theory, the continuous delivery of avolatile material may be a function of various factors includingmembrane pore size; membrane surface area; the physical properties of avolatile material, such as molecular weight and saturation vaporpressure (“VP”); and the viscosity and/or surface tension of thecomposition containing the volatile material.

The composition may be formulated such that the composition comprises avolatile material mixture comprising about 10% to about 100%, by totalweight, of volatile materials that each having a VP at 25° C. of lessthan about 0.01 torr; alternatively about 40% to about 100%, by totalweight, of volatile materials each having a VP at 25° C. of less thanabout 0.1 torr; alternatively about 50% to about 100%, by total weight,of volatile materials each having a VP at 25° C. of less than about 0.1torr; alternatively about 90% to about 100%, by total weight, ofvolatile materials each having a VP at 25° C. of less than about 0.3torr. In one embodiment, the volatile material mixture may include 0% toabout 15%, by total weight, of volatile materials each having a VP at25° C. of about 0.004 torr to about 0.035 torr; and 0% to about 25%, bytotal weight, of volatile materials each having a VP at 25° C. of about0.1 torr to about 0.325 torr; and about 65% to about 100%, by totalweight, of volatile materials each having a VP at 25° C. of about 0.035torr to about 0.1 torr. One source for obtaining the saturation vaporpressure of a volatile material is EPI Suite™, version 4.0, availablefrom U.S. Environmental Protection Agency.

Two exemplary compositions comprising a volatile material mixture havingvolatile materials of varying VPs are set forth below in Tables 1 and 2.These compositions are shown by way of illustration and are not intendedto be in any way limiting of the invention.

TABLE 1 Wt % Low VP (torr) High VP (torr) 27.71 0.175 0.325 20.78 0.08750.1125 13.86 0.0625 0.0875 8.66 0.0375 0.0625 8.66 0.0175 0.0325 6.930.00875 0.01125 6.93 0.00625 0.00875 3.18 0.00375 0.00625 1.27 0.001750.00325 0.95 0.000875 0.001125 0.64 0.000625 0.000875 0.32 0.0003750.000625 0.09 0.000175 0.000325

TABLE 2 Wt % Low VP (torr) High VP (torr) 33.38 0.175 0.325 25.75 0.08750.1126 19.07 0.0625 0.0875 13.86 0.0375 0.0625 4.00 0.0175 0.0325 1.500.00875 0.01125 0.50 0.00625 0.00875 0.72 0.00375 0.00625 0.55 0.001750.00325 0.27 0.000875 0.001125 0.20 0.000625 0.000875 0.13 0.0003750.000625 0.07 0.000175 0.000325

The viscosity of a volatile material may control how and when a volatilematerial is delivered to the breathable membrane 140. For example, lessviscous compositions may flow faster than the more viscous volatilematerials. Thus, the membrane may be first wetted with the less viscousmaterials. The more viscous volatile material, being slightly less or ofsimilar density with the less viscous phase, may remain in thecollection basin 112 via gravity. Thus, the less viscous volatilematerial may be delivered to the breathable membrane 140 and emitted tothe atmosphere more quickly. To help prevent liquid from seeping throughthe breathable membrane 140, volatile materials may have viscositiesless than about 23 cP and surface tension less than about 33 mN/m.

In one embodiment, the composition containing a volatile material mayhave a viscosity of about 1.0 cP to less than about 25 cP, alternativelyabout 1.0 cP to less than about 23, alternatively about 1.0 cP to lessthan about 15 cP.

The composition containing a volatile material may be designed such thatthe composition may include a surface tension of about 19 mN/m to lessthan about 33 mN/m, alternatively about 19 mN/m to less than about 30mN/m, alternatively about 19 mN/m to less than about 27 mN/m.

EXAMPLES

The following examples are not to be construed as limitations of thepresent invention since many variations thereof are possible withoutdeparting from its spirit and scope.

Example 1

In this example, two identical air freshening delivery engines aredesigned utilizing a Daramic V5 membrane with an evaporative surfacearea of approximately 34 cm². Two perfume compositions, RJJ-577 andRJJ-573-8, each having a volatile material mixture with volatilematerials of different VP ranges are tested in the air fresheningdelivery engines for evaporation rates. The VP ranges of the volatilematerials are shown in Tables 3 and 4.

TABLE 3 RJJ-577 VP VP 25° C. 25° C. Low High Wt % 0 0.001 0.2 0.001 0.010.0 0.01 0.1 3.4 0.1 0.3 28.6 0.3 10 64.8

TABLE 4 RJJ-573-8 VP VP 25° C. 25° C. Low High Wt % 0 0.001 1.9 0.0010.01 8.5 0.01 0.1 32.6 0.1 0.3 49.8 0.3 10 6.8

One delivery engine is loaded with 6000 mg of perfume compositionRJJ-577; the other with 6000 mg of perfume composition RJJ-573-8.RJJ-577 includes relatively higher VP components than RJJ-573-8. Eachfilled delivery engine is weighed; weight is recorded. Both deliveryengines are placed into housings and held in a room at 21° C. At thetimes indicated on FIG. 10 , the delivery engine is weighed; weightrecorded. FIG. 10 shows that after about two weeks, the evaporation rateof RJJ-577 has almost flattened which would then require anotherdelivery engine. This would be costly and may be viewed as burdensome byconsumers. On the other hand, perfume RJJ-573-8 with a microporousmembrane delivers consistent linear intensity over a longer period oftime.

Example 2

In this example, two air freshening delivery engines are constructedutilizing different membranes. Each is tested for evaporation ratesusing RJJ-573-8, which was utilized in Example 1. 6000 mg of RJJ-573-8is loaded into a delivery engine with a low density polyethylenemembrane (LDPE) having an average pore size of about 40 microns. 6000 mgof RJJ-573-8 is loaded into a delivery engine having a Daramic V5microporous membrane. As can be seen from FIG. 11 , the microporousmembrane is much more efficient in releasing the relatively low vaporpressure perfume than the LDPE membrane. Thus, utilizing a microporousmembrane in accordance with the present invention delivers higherintensities of lower vapor pressure (i.e. more pleasing “base note”perfume raw materials can be delivered).

Every numerical range given throughout this specification will includeevery narrower numerical range that falls within such broader numericalrange, as if such narrower numerical range were all expressly writtenherein. Further, the dimensions and values disclosed herein are not tobe understood as being strictly limited to the exact numerical valuesrecited. Instead, unless otherwise specified, each such dimension isintended to mean both the recited value and a functionally equivalentrange surrounding that value. For example, a dimension disclosed as “40mm” is intended to mean “about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed:
 1. An apparatus for delivering a volatile materialcomprising: a delivery engine having a reservoir comprising a volatilematerial mixture, said mixture comprising a volatile material mixture; amicroporous membrane enclosing said reservoir; and a rupturablesubstrate enclosing said reservoir; a rupture element comprising asupport structure, wherein the rupture element is configured to engagethe rupturable substrate; a housing for receiving said delivery engine,wherein the housing comprises a plurality of vents for facilitating thediffusion of volatile materials from the microporous membrane.
 2. Theapparatus of claim 1, wherein said delivery engine further comprises acollection basin in fluid communication with said microporous membraneand said reservoir upon rupturing said rupturable substrate.
 3. Theapparatus of claim 1, wherein said rupture element comprises acompressible flange.
 4. The apparatus of claim 3, wherein saidcompressible flange comprises a distal end and a piercing element, saidpiercing element positioned on said distal end.
 5. The apparatus ofclaim 1, wherein said rupture element comprises a compression force tobreach said rupturable substrate of less than about 15N.
 6. Theapparatus of claim 1, wherein said microporous membrane comprises anaverage pore size of about 0.02 microns.
 7. The apparatus of claim 1,wherein said microporous membrane comprises an evaporative surface areaof about 15 cm² to about 35 cm².
 8. The apparatus of claim 1, whereinsaid microporous membrane comprising an average pore size of about 0.01to about 0.03 microns.
 9. The apparatus of claim 1, wherein saidmicroporous membrane comprises an evaporative surface area of about 15cm² to about 35 cm².
 10. The apparatus of claim 1, wherein said ruptureelement comprises a compression force to breach said rupturablesubstrate of less than about 25N.
 11. The apparatus of claim 1, whereinsaid rupture element comprises a compression force to breach saidrupturable substrate of less than about 20N.
 12. The apparatus of claim1, wherein said rupture element comprises a compression force to breachsaid rupturable substrate of less than about 10N.
 13. The apparatus ofclaim 1, wherein said rupture element comprises a compression force tobreach said rupturable substrate of from about 1N to about 15N.
 14. Theapparatus of claim 1, wherein said rupture element comprises acompression force to breach said rupturable substrate of from about 1N,to about 10N.
 15. The apparatus of claim 1, wherein said rupture elementcomprises a compression force to breach said rupturable substrate offrom about 1N to about 5N.
 16. The apparatus of claim 1, wherein themicroporous membrane comprises polyethylene.
 17. The apparatus of claim16, wherein the microporous membrane comprises a thickness in az-direction of from about 0.01 mm to about 1 mm.
 18. The apparatus ofclaim 16, wherein the microporous membrane comprises a thickness in az-direction of from about 0.1 mm to 0.4 mm.
 19. The apparatus of claim16, wherein the microporous membrane comprises a thickness in az-direction of from about 0.15 mm to about 0.35 mm.